<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <style>
    .red{
      color : red;
    }
    .big-font{
      font-size: 50px;
    }
    .underlines{
      text-decoration: underline;
    }
  </style>
</head>
<body>
  <p class="big-font red">段落1</p>
  <p class="red underlines">段落2</p>
  <p class="big-font underlines">段落3</p>
  <p class="big-font underlines red">段落4</p>
</body>
</html>